1. Field of the Invention
The present invention relates to novel cephalosporin derivatives for oral administration, and more particularly to cephalosporin derivatives and their non-toxic salts showing excellent antibacterial effect by oral administration.
2. Description of the Prior Art
Cephalosporin drugs are widely used for the treatment and prevention of various infectious diseases caused by pathogenic bacteria.
Especially, since the cephalosporin drugs for oral administration, represented by cefalexin, can be more easily used than the cephalosporin drugs for injectional administration, they are most widely used now. Compounds having certain vinylthio substituents at the 3-position of cephalosporin derivatives are disclosed more recently (U.K. Pat. No. 2,144,420A).
However, known cephalosporin drugs for oral administration are much inferior to the cephalosporin drugs for injectional administration in terms of antibacterial activity and antibacterial spectrum, and the problem is the remarkable increase of resistance strains to these drugs.
Under such circumstances, it is desired to discover cephalosporin drugs having excellent antibacterial activity, wide antibacterial spectrum, and absorption in effective amounts into the blood concentration.